You're welcome and I hope all goes well. I noticed you mentioned dry ice, would the purpose of this be as a cooling agent to help precipitation?

I don't really have the expertise to advise on this, but perhaps your end product may not be as pure, due to the low temperatures enabling the impurities to precipitate along with the spice.

I'm also not sure what effect this would have on the naphtha as far as freezing goes, but it may have some effect on this. There will be other members with more expertise who can give you a better answer, so please don't hold me to it.

Please do let us know how you get on, and post pics

Peace

Macre